Nan Galbraith wrote:
> Steve Hankin wrote:
>> Its approaching two weeks (Oct 27) since a revised "CF point
>> observation Conventions" proposal was made:
>>
>> https://cf-pcmdi.llnl.gov/trac/wiki/PointObservationConventions
>>
>> https://cf-pcmdi.llnl.gov/trac/ticket/37
>>
>> Given the complexity of the proposal, it would be helpful if
>> discussion happened sooner than later, including statements of
>> support or issues to be resolved. Input is especially important from
>> data providers who actually write point observation files.
> I haven't commented on this new version because, as far as I understand
> it, it will not work for data from surface moorings, and therefore won't
> apply to most of the datasets in projects I'm involved with.
>
> IF this is intended to be used for time series at multiple depths,
> then the
> definition of "stationTimeSeries" would need to be changed from "a
> time-series of data points at the same location" to "a time-series of
> data
> points at the same X-Y location" - to make it more clear that this type
> can hold time series data at multiple depths. The example would also
> need to show how a dependent variable would be dimensioned to hold
> 2d data at each station.
>
> In recent discussions on this list, it looks almost like there's some
> idea
> that the "profile" feature type should be used for this kind of data.
> That
> would be a very hard sell. The term profile, as used in the observational
> community, is very different from time series - most importantly, it
> indicates that Z varies with T. If moored station data is meant to be
> covered by this specification, and if it won't fit into the "station"
> feature
> type, a term other than profile should be used.
>
> Cheers - Nan
>
Hi Nan:
The proposal is intended to work with surface moorings, so if it doesnt
work, lets understand why.
I think your data would probably be classified as stationProfile data:
"a time-series of profiles at a named location". A single file can
contain one or a collection of surface moorings data. See section 9.6
for representations.
I think you are being misled by the word "profile", which apparently has
a different meaning in your community. In this proposal, a profile is a
series of point measurements at different z, with the same x,y. There
may be a single time for each profile, or time may depend on z. It
sounds like the former is true in your case.
Assuming that the semantics fits, i wouldnt be overly concerned if the
name "stationProfile" is a bit misleading. You will have to add a global
attribute
:CF:featureType = "stationProfile";
to your file, and follow one of the representations in section 9.6, but
otherwise the variable and dimension names can use whatever terminology
makes sense to your community. If you want to send a sample (perhaps
simplified) CDL, we could see what it would look like under this proposal.
Regards,
John
Received on Thu Nov 12 2009 - 10:52:27 GMT
